var startTag = /^<([-A-Za-z0-9_]+)((?:\s+[a-zA-Z_:][-a-zA-Z0-9_:.]*(?:\s*=\s*(?:(?:"[^"]*")|(?:'[^']*')|[^>\s]+))?)*)\s*(\/?)>/,
  endTag = /^<\/([-A-Za-z0-9_]+)[^>]*>/,
  attr = /([a-zA-Z_:][-a-zA-Z0-9_:.]*)(?:\s*=\s*(?:(?:"((?:\\.|[^"])*)")|(?:'((?:\\.|[^'])*)')|([^>\s]+)))?/g;
var empty = makeMap('area,base,basefont,br,col,frame,hr,img,input,link,meta,param,embed,command,keygen,source,track,wbr');

var block = makeMap(
  'a,address,article,applet,aside,audio,blockquote,button,canvas,center,dd,del,dir,div,dl,dt,fieldset,figcaption,figure,footer,form,frameset,h1,h2,h3,h4,h5,h6,header,hgroup,hr,iframe,ins,isindex,li,map,menu,noframes,noscript,object,ol,output,p,pre,section,script,table,tbody,td,tfoot,th,thead,tr,ul,video'
);
var inline = makeMap(
  'abbr,acronym,applet,b,basefont,bdo,big,br,button,cite,code,del,dfn,em,font,i,iframe,img,input,ins,kbd,label,map,object,q,s,samp,script,select,small,span,strike,strong,sub,sup,textarea,tt,u,var'
);

var closeSelf = makeMap('colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr');

var fillAttrs = makeMap('checked,compact,declare,defer,disabled,ismap,multiple,nohref,noresize,noshade,nowrap,readonly,selected');

var special = makeMap('script,style');

function HTMLParser(html, handler) {
  var index,
    chars,
    match,
    stack = [],
    last = html;
  stack.last = function () {
    return this[this.length - 1];
  };

  while (html) {
    chars = true;

    if (!stack.last() || !special[stack.last()]) {
      if (html.indexOf('<!--') == 0) {
        index = html.indexOf('-->');

        if (index >= 0) {
          if (handler.comment) handler.comment(html.substring(4, index));
          html = html.substring(index + 3);
          chars = false;
        }
      } else if (html.indexOf('</') == 0) {
        match = html.match(endTag);

        if (match) {
          html = html.substring(match[0].length);
          match[0].replace(endTag, parseEndTag);
          chars = false;
        }
      } else if (html.indexOf('<') == 0) {
        match = html.match(startTag);

        if (match) {
          html = html.substring(match[0].length);
          match[0].replace(startTag, parseStartTag);
          chars = false;
        }
      }

      if (chars) {
        index = html.indexOf('<');

        var text = index < 0 ? html : html.substring(0, index);
        html = index < 0 ? '' : html.substring(index);

        if (handler.chars) handler.chars(text);
      }
    } else {
      html = html.replace(new RegExp('([\\s\\S]*?)</' + stack.last() + '[^>]*>'), function (all, text) {
        text = text.replace(/<!--([\s\S]*?)-->|<!\[CDATA\[([\s\S]*?)]]>/g, '$1$2');
        if (handler.chars) handler.chars(text);

        return '';
      });

      parseEndTag('', stack.last());
    }

    if (html == last) throw 'Parse Error: ' + html;
    last = html;
  }

  parseEndTag();

  function parseStartTag(tag, tagName, rest, unary) {
    tagName = tagName.toLowerCase();

    if (block[tagName]) {
      while (stack.last() && inline[stack.last()]) {
        parseEndTag('', stack.last());
      }
    }

    if (closeSelf[tagName] && stack.last() == tagName) {
      parseEndTag('', tagName);
    }

    unary = empty[tagName] || !!unary;

    if (!unary) stack.push(tagName);

    if (handler.start) {
      var attrs = [];

      rest.replace(attr, function (match, name) {
        var value = arguments[2] ? arguments[2] : arguments[3] ? arguments[3] : arguments[4] ? arguments[4] : fillAttrs[name] ? name : '';

        attrs.push({
          name: name,
          value: value,
          escaped: value.replace(/(^|[^\\])"/g, '$1\\"')
        });
      });

      if (handler.start) handler.start(tagName, attrs, unary);
    }
  }

  function parseEndTag(tag, tagName) {
    var pos = 0;
    if (!tagName) {
      pos = 0;
    } else for (pos = stack.length - 1; pos >= 0; pos--) if (stack[pos] == tagName) break;

    if (pos >= 0) {
      for (var i = stack.length - 1; i >= pos; i--) if (handler.end) handler.end(stack[i]);

      stack.length = pos;
    }
  }
}

function makeMap(str) {
  var obj = {},
    items = str.split(',');
  for (var i = 0; i < items.length; i++) obj[items[i]] = true;
  return obj;
}

function q(v) {
  return '"' + v + '"';
}

function changeMap() {
  return 'u,a,abbr,b,blockquote,br,code,col,span,colgroup,span,dd,del,div,dl,dt,em,fieldset,h1,h2,h3,h4,h5,h6,hr,i,img,ins,label,legend,li,ol,p,q,span,strong,sub,sup,table,tbody,td,tfoot,th,thead,tr,ul'.split(
    ','
  );
}
var styleMap = 'color,font,background,text,padding,margin'.split(',');

function styleFilter(style) {
  return styleMap.some(a => style.startsWith(a));
}

function removeDOCTYPE(html) {
  return html
    .replace(/<\?xml.*\?>\n/, '')
    .replace(/<!doctype.*>\n/, '')
    .replace(/<!DOCTYPE.*>\n/, '');
}

export default function (html) {
  if (!html) return '';
  var map = changeMap();
  html = removeDOCTYPE(html);
  var bufArray = [];
  var results = {
    node: 'root',
    children: []
  };
  try {
    HTMLParser(html, {
      start: function (name, attrs, unary) {
        var node = {
          type: 'node',
          name: name
        };
        if (map.indexOf(name) < 0) {
          node.name = 'div';
        }

        node.attrs = {};
        if (attrs.length !== 0) {
          node.attrs = attrs.reduce(function (pre, attr) {
            var name = attr.name;
            var value = attr.value;
            switch (name) {
              case 'class':
                if (value.match(/ /)) {
                  value = value.split(' ');
                }
                if (pre[name]) {
                  if (Array.isArray(pre[name])) {
                    pre[name].push(value);
                  } else {
                    pre[name] = [pre[name], value];
                  }
                } else {
                  pre[name] = value;
                }
                break;
              case 'style':
                if (value) {
                  var array = value.split(';');
                  var list = [];
                  array.forEach(a => {
                    if (styleFilter(a)) {
                      list.push(a);
                    }
                  });
                  pre[name] = list.join(';');
                }
                break;
              case 'src':
              case 'colspan':
              case 'rowspan':
                pre[name] = value;
                break;
              default:
                console.warn('不支持的节点：' + name + '=' + value);
                break;
            }
            return pre;
          }, {});
        }
        node.attrs.class = name;
        if (unary) {
          var parent = bufArray[0] || results;
          if (parent.children === undefined) {
            parent.children = [];
          }
          parent.children.push(node);
        } else {
          bufArray.unshift(node);
        }
      },
      end: function (name) {
        var node = bufArray.shift();
        if (map.indexOf(name) < 0) {
          name = 'div';
        }
        if (node.name !== name) console.error('丢失结束标签' + name);
        if (bufArray.length === 0) {
          results.children.push(node);
        } else {
          var parent = bufArray[0];
          if (parent.children === undefined) {
            parent.children = [];
          }
          parent.children.push(node);
        }
      },
      chars: function (text) {
        var node = {
          type: 'text',
          text: text
        };
        if (bufArray.length === 0) {
          results.children.push(node);
        } else {
          var parent = bufArray[0];
          if (parent.children === undefined) {
            parent.children = [];
          }
          parent.children.push(node);
        }
      },
      comment: function (text) {
        var node = {
          type: 'comment',
          text: text
        };
        var parent = bufArray[0];
        if (parent.children === undefined) {
          parent.children = [];
        }
        parent.children.push(node);
      }
    });
  } catch (e) {
    console.warn(e);
  }
  return results.children;
}
